ios - 如何在应用程序切换器/关闭器栏上方设置输入附件 View 的约束？

Question

我很难将我的 inputAccessoryView 限制在 iPhoneX 屏幕(和其他缺口设备)的底部安全区域上方。我有一个 UICollectionViewController，它的 inputAccessoryView 是一个 UIView，其中包含一个 UITextView 和 2 个 UIButtons。基本上，该布局适用于聊天应用程序。当我运行当前代码时，inputAccessoryView 没有出现在屏幕底部的安全区域上方。它目前固定在屏幕底部。附截图。

如您所见，底部的应用程序切换器/关闭器栏与我的 inputAccessoryView 重叠。我想让 inputAccessoryView 位于上述栏之上。

这是我当前的代码(与约束相关):

class NewMessagesViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
    private lazy var inputTextField: UITextField = {
        let textField = UITextField()
        textField.placeholder = "Enter message"
        textField.translatesAutoresizingMaskIntoConstraints = false
        textField.delegate = self
        return textField
    }()
    private lazy var inputContainerView: UIView = {
        let margin = view.layoutMarginsGuide
        let safeArea = view.safeAreaInsets

        let containerView = UIView()
        containerView.frame = CGRect(x: 0, y: 0, width: self.view.frame.width, height: 50)
        containerView.backgroundColor = .white

        let uploadImageView = UIImageView()
        uploadImageView.isUserInteractionEnabled = true
        uploadImageView.image = UIImage(named: "image")
        uploadImageView.translatesAutoresizingMaskIntoConstraints = false
        uploadImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleUploadTap)))
        containerView.addSubview(uploadImageView)
        uploadImageView.leftAnchor.constraint(equalTo: containerView.leftAnchor).isActive = true
        uploadImageView.centerYAnchor.constraint(equalTo: containerView.centerYAnchor).isActive = true
        uploadImageView.widthAnchor.constraint(equalToConstant: 44).isActive = true
        uploadImageView.heightAnchor.constraint(equalToConstant: 44).isActive = true

        let sendButton = UIButton(type: .system)
        sendButton.setTitle("Send", for: .normal)
        sendButton.translatesAutoresizingMaskIntoConstraints = false
        sendButton.addTarget(self, action: #selector(sendText), for: .touchUpInside)
        containerView.addSubview(sendButton)
        // x,y,w,h
        sendButton.rightAnchor.constraint(equalTo: containerView.rightAnchor).isActive = true
        sendButton.centerYAnchor.constraint(equalTo: containerView.centerYAnchor).isActive = true
        sendButton.widthAnchor.constraint(equalToConstant: 80).isActive = true
        sendButton.heightAnchor.constraint(equalTo: containerView.heightAnchor).isActive = true

        containerView.addSubview(self.inputTextField)
        self.inputTextField.leftAnchor.constraint(equalTo: uploadImageView.rightAnchor, constant: 8).isActive = true
        self.inputTextField.centerYAnchor.constraint(equalTo: containerView.centerYAnchor).isActive = true
        self.inputTextField.rightAnchor.constraint(equalTo: sendButton.leftAnchor).isActive = true
        self.inputTextField.heightAnchor.constraint(equalTo: containerView.heightAnchor).isActive = true

        let separatorLineView = UIView()
        separatorLineView.backgroundColor = UIColor(red: 220, green: 220, blue: 220)
        separatorLineView.translatesAutoresizingMaskIntoConstraints = false
        containerView.addSubview(separatorLineView)
        separatorLineView.leftAnchor.constraint(equalTo: containerView.leftAnchor).isActive = true
        separatorLineView.topAnchor.constraint(equalTo: containerView.topAnchor).isActive = true
        separatorLineView.widthAnchor.constraint(equalTo: containerView.widthAnchor).isActive = true
        separatorLineView.heightAnchor.constraint(equalToConstant: 1).isActive = true

        return containerView
    }()

    override var inputAccessoryView: UIView? {
        get {
            return inputContainerView
        }
    }

    override var canBecomeFirstResponder: Bool {
        return true
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        self.navigationItem.title =  ticket.subject

        collectionView.keyboardDismissMode = .interactive
    }
}

我已经尝试将 UITextField 和 UIButton 的 底部 anchor 约束约束为等于 viewDidLoad() 中的 view.layoutMarginsGuide.bottomAnchor 但这只是使我的应用程序因错误而崩溃:

*** Terminating app due to uncaught exception 'NSGenericException', reason: 'Unable to activate constraint with anchors <NSLayoutYAxisAnchor:0x28204dac0 "UIImageView:0x107417780.bottom"> and <NSLayoutYAxisAnchor:0x2820270c0 "UILayoutGuide:0x280c8cb60'UIViewLayoutMarginsGuide'.bottom"> because they have no common ancestor.  Does the constraint or its anchors reference items in different view hierarchies?  That's illegal.'

如果有人可以提供有关如何正确限制应用程序切换器/关闭器栏上方的 inputAccessoryView 的代码片段，我们将不胜感激。

Answer 1

使用 SafeArea 设置 CollectionView 底部约束，这将解决您的问题。